So is this a stark example of the same old wimpy, industry-driven U.S. Food and Drug Administration? Or does it signal a turn toward taking action to protect consumers when the data suggest (but don’t prove) that a popular drug may be risky?

“Europe has taken Avandia off the market, which is what the FDA should have done,” e-mails Diana Zuckerman, who represents a consortium of consumer groups.

There may be fewer differences between the action taken by European and U.S. regulators than you might think at first glance.

By clamping such serious restrictions on who can get Avandia in the future, the FDA has essentially killed the once-upon-a-time blockbuster. Even its maker GlaxoSmithKline conceded as much.

In a statement, Glaxo said it “will voluntarily cease promotion of Avandia in all the countries in which it operates and will continue to respond to requests for information and support from healthcare professionals and patients.”

The drugmaker expects Avandia sales to all but vanish by next year, despite the possibility that some American patients could still have access to the medicine.

How scant might sales be? “Minimal could be zero,” says Dr. Cliff Rosen of Maine Medical Center. “What they did today is really close to almost total restriction of the drug. I mean, a physician has to get informed consent and really document why they would put a patient on this drug. That’s really tough.”

Based on pre-decision scuttlebutt, Rosen was girding for a very different outcome – merely a change in the wording of Avandia’s label. He wasn’t alone.

That’s what Dr. Steve Nissen of Cleveland Clinic, was expecting too. He’s one of Avandia’s (and the FDA’s) most prominent critics. Today, Nissen told the Wall Street Journal, “I think it’s a reasonable course of action and compromise. It will limit 99% of its use.”

In putting new restrictions on prescribing Avandia, FDA followed the advice of many of its own advisers, including Rosen, a panelist. In July, 10 of 33 members of an FDA advisory committee said if Avandia was to remain on the market, it be with severe restrictions. Another dozen voted to take it off the market, seven wanted just label changes, and just three said do nothing. There was one abstention.

Rosen, who later wrote a commentary in the New England Journal of Medicine urging the action the FDA ended up taking, says he feels listened to.

There’s no question Avandia nearly tore the agency apart. Some factions were dead-set against severe restrictions, not to mention taking the drug off the market.

In announcing the decision, FDA Commissioner Dr. Margaret Hamburg alluded to the “passionate discussion” Avandia provoked, both inside FDA and among outside scientists and clinicians.

“As FDA commissioner, my job would be infinitely easier if we had consensus and full scientific clarity,” she said.

But in the realm of drug safety, that’s rarely the case – especially when excess risks on the order of 30 or 40 percent arise, as in this case, after a drug is already widely prescribed.

The Avandia story is replete with dueling studies, delayed studies, concealed studies, studies that were supposed to answer the safety questions, but didn’t.

In fact, that frustrating process will continue. The FDA has asked Glaxo to do another review of its highly criticized centerpiece study, called RECORD, that was supposed to settle the question of whether Avandia causes more heart problems. It’s not clear where that will lead, except to more debate.

Rosen predicts more Avandia-type dilemmas in FDA’s future, because scientists are getting better at extracting risk “signals” from various kinds of studies.

“If there’s any signal, finding that signal and then trying to decide what to do with it now much more in our grasp that a few years ago,” he says. “So I think we’re going to see this much more frequently.”